The present invention relates to element analysis systems, and more particularly to a field portable X-ray fluorescent spectrometer.
X-ray fluorescent spectrometers have long been used to analyze the elemental composition of mineral samples taken during geological surveys. In operation, the unknown mineral samples are irradiated in order to cause them to fluoresce, and the resulting fluorescent X-ray radiation is analyzed with a multichannel radiation analyzer. The multichannel analyzer accumulates a spectrum representing the energy distribution of the fluorescent radiation. The profile of the energy spectrum thus obtained will be determined by the elemental composition of the sample. Thus, the elemental composition of the sample can then be determined by comparing the spectrum with other spectrums obtained from samples of known composition.
Due to the not inconsiderable size of these X-ray fluorescent spectrometers, the practice has heretofore been to install the X-ray fluorescent spectrometer at a fixed location, often quite distant from the area being surveyed. Specimens collected in the field thus had to be transported to the spectrometer for analysis. Furthermore, the specimens often had to be processed (as by pulverizing them) before analysis could begin. The pinpointing of a particular mineral concentration was thus a lengthy process, since it might be necessary to make multiple trips to the survey site in order to obtain samples from slightly different areas than those from which the initial samples had been collected. To reduce survey time, then, it was important that the surveyor collecting the samples draw upon his own experience to provide a visual, first order analysis of the mineral content of the samples being collected. Experience of the surveyor was therefore a factor of considerable importance.
Several miniature element analysis units utilizing the property of X-ray fluorescence were developed for use in space exploration, and are now being used in the two Viking landers presently operating on the surface of the planet Mars. Unfortunately, these X-ray fluorescent spectrometers were designed solely to acquire and transmit raw spectrographic data, and could not be used to provide a meaningful analysis of mineral samples in a field portable, man-in-the-loop system. Thus, the data acquired by the Viking Mars landers is processed in a large scale, Earth-based data processing computer.